Allow the user to use a custom world passed by launch argument

[francocipollone]

Summary

Allow the user to use a custom world passed by launch argument

Suggestion

ros2 launch andino_gz andino_gz.launch.py world_path:=<path/to/custom/map>

Alternative

What if we add the worlds folder to the GZ_RESOURCE_PATH (via env hook) and let gazebo to pick up the sdf from there.

So the user in order to use the world they just have to add the world to the GZ_RESOURCE_PATH and use the name of their custom world.